Skid mounted heater



2, 1965 E. R. MUCKELRATH 3,263,979

SKID MOUNTED HEATER Filed June 5, 1965 2 SheetsSheet l l- -4 Fig I? 36' 32 Fig. 2

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Aug 2, 1966 E. R. MUCKELRATH 3,263,979

SKID MOUNTED HEATER Filed June 3, 1965 2 Sheets-Sheet 2 Fig. 3

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United States Patent Office Patented August 2, 1966 3,263,979 SKID MOUNTED HEATER Ernest R. Muckelrath, Tioga, N. Dak., assignor to Air Heaters, Inc., a corporation of North Dakota Filed June 3, 1965, Ser. No. 461,072 8 Claims. (Cl. 263-19) The instant invention generally relates to heater assemblies, and is a continuation-in-part of app'licants copending application for Portable Heater, Serial No. 288,321, filed June 17, 1963, now Patent No. 3,201,098.

It is a primary object of the instant invention to provide a portable heating uni-t which is specifically adapted for heating outdoor areas so as to maintain temperatures which allow a continuation of the work under reasonably comfortable conditions. As will be appreciated, the provision of such an area heater at drilling rigs, outdoor construction jobs, or for that matter any place where men must work outdoors in extremely cold weather or where machinery must be started and operated, can constitute a valuable asset.

In conjunction with the above object, it is also a highly significant object of the instant invention to provide a heating unit, from which a constant temperature large volume of heated air is supplied, which includes a completely concealed fire and means for ensuring a complete combustion of the fuel, thereby eliminating any potential danger which might arise, especially when working in and about oil or gas fields.

Another significant object of the instant invention is to provide for the introduction and heating of a large amount of fresh and, to some degree, preheated air into the fire tube in a manner which ensures a complete combustion of the fuel and at the same time prevents a build up of static pressure such as might result in an accumulation of an explosive mixture within the fire tube or duct.

In conjunction with the introduction of a large volume of fresh air, it is also a significant object of the instant invention that this be done forwardly of the burner and in a manner which, while ensuring a complete combustion, does not affect the operation of the burner itself.

In addition, it is 'a significant object of the instant invention to provide a heater which economically produces a dependable and continuous high discharge temperature regardless of extremes in the ambient weather.

It is also a significant object of the instant invention to provide a heater which can be utilized to provide safe and effective heat for personnel and machinery within enclosed areas, and which at the same time, due to the high volume and velocity of air being discharged, displace or drive out any accumulated undesirable fumes.

Furthermore, it is a significant object of the instant invention to provide an area heater wherein no water is required in the heating system, no return system is incorporated therein, and the heated air is delivered in a manner which causes little moisture accumulation.

Also, it is a significant object of the instant invention to provide a portable heater which is of a relatively simple and highly rugged nature capable of efiiciently functioning notwithstanding the rough treatment to which it will normally be subjected.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a top plan view of the area heater comprising the instant invention with portions broken away for purposes of illustration;

FIGURE 2 is a side elevational view of the heater illustrating the exhaust or outlet end of the blower;

FIGURE 3 is an elevational view of the opposite side of the device;

FIGURE 4 is a cross-sectional view taken substantially on a plane passing along line 44 in FIGURE 1; and

FIGURE 5 is a cross-sectional view taken substantially on a plane passing along line 5-5 in FIGURE 4.

Referring now more specifically to the drawings, reference numeral 10 generally designates the portable area heater comprising the instant invention. Basically, the heater of the instant invention includes an elongated fire tube or duct 12, a burner unit 14 mounted within one end thereof, a blower unit 16 mounted on the other end thereof, a power plant 18, a supporting frame or rack 20 for the blower extension tubes or ducts 22, and a skid base or bed 24 mounting these elements for movement as a unit.

The skid bed 24 itself consists of three elongated laterally spaced parellel I-beams 26 interconnected by a plurality of transversely extending rigid pipes 28 welded to the webs of the I-beams 26. As will be noted from the drawings, the opposite ends of the bed I-beams 25 are rounded so as to facilitate movement of the heater It) over the various different terrains which will be encountered, with the front and rear transverse pipe braces 28, through the rounded surfaces thereof, further facilitating the movement of the unit.

The heater tube 12 is supported above the bed 24 by pairs of diverging legs 30 spaced along the length thereof, the tube 12 overyling approximately one-half of the length of the bed 24. As will be best appreciated from FIG- URES l and 2, the fire tube 12 is generally U-shaped in plan including two spaced parallel legs and a right angularly related bight portion. One of the legs of the fire tube 12, that within which the burner unit 14 is mounted, consists of an independent section 32 spaced longitudinally from and in coaxail alignment with the adjoining portion of the second or larger section of the tube 12, thereby defining an enlarged completely open air intake opening 36 therebetween. The entire duct or fire tube 12, including both sections 32 and 34, is of a constant crosssectional area throughout the entire length thereof. The first section 32 includes an inlet end portion which defines the duct inlet end 38, and an outlet end portion 40 spaced from the inlet end portion 42 of the second section 34, there-by defining the air intake opening between the sections 32 and 34. In addition, the second section 34 also of course includes an outlet end portion which defines the duct outlet 44.

The inlet end 38 of the fire tube 12 includes a top fixed closure plate 46 to which is hinged an enlarged closure plate 48, both of which combine so as to close off the duct inlet end 38.

The hinged closure plate or door 48 includes a centrally located combination air intake and observation hole 50 which is located immediately behind the burner head or fuel injection means 52 attached, through a conduit 54, to a suitable fuel supply which may be natural gas, liquid petroleum gas, diesel fuel oil, crude oil, etc. The burner head 52 is mounted on a frame or platform 56 which spans the tube section 32 adjacent the intake end 38 and is welded to the opposite sides thereof through downwardly arced flanges 58. Incidentally, as will be appreciated from the cross-sectional view of FIGURE 4, two or more burner heads 52 can be provided as desired. A second opening 60 is provided through the bottom of the section 32 adjacent the outlet end 38 so as to provide an additional air intake and allow for the introduction of the burner head conduits 54, the openings 50 and 60 combining to allow for the introduction of the primary combustion supporting air just to the rear of the burner heads 52. Incidentally, the hinged closure panel 48 will of course be provided with a suitable retaining latch.

The blower 16, powered by the power unit 18, which can be of any suit-able type such as gas or electric, includes an intake or inlet 62 positioned against and directly communicating with the duct outlet 44, and an outlet 64 extending laterally therefrom and laterally from the unit with this blower outlet 64 accommodating any suitable number of extensions 22. With regard to these blower pipe or tube extensions 22, as noted supra, when not in use, they are stored overhead on the supporting frame or rack 20 which consists of a plurality of longitudinally extending I-beams 66, upon which the tubular extensions 22 rest, side rails 68 retaining the tubes 22 on the I-beam floor, and support columns 7 0' which operate in conjunction with the the tube housing 72 to position the rack 20 above the heater equipment.

With regard to the housing 72, it will be noted that this housing is constructed of a rigid angle iron frame 74 and an insulated corrugated metal top 76 and bottom 78, as well as two similarly formed side walls 80 and 82 and two similarly formed end walls 84 and 86. In this manner, a housing rectangular in shape is formed. As will be appreciated from the drawings, the housing 72 encloses the entire fire tube 12 aside from that portion thereof immediately adjacent both the intake and outlet ends 38 and 44 thereof. In this manner, the burner end of the tube 12, as well as the burner head 52 located therein, is easily accessible, as is the blower end of the tube along with the various temperature and air controls and gages 88 mounted on the outlet end port-ion of the tube 12 exteriorly of the housing 72.

In order to provide for a constant supply of air to the enlarged air intake opening 36 provided between the adjacent ends 40 and 42 of the duct sections 32 and 34, two enlarged screened openings 90 and 92 are provided through the housing 72. The opening 90 is located through the insulated top 76 directly above the duct air intake opening 36, while the opening 92 is located in the lower forward corner of the insulated sidewall 80, this being the sidewall adjacent the intake side of the duct 12. With such an arrangement, it will be appreciated that the air drawn into the air intake opening 36 by the blower 16, this air constituting secondary combustionsupporting air, will to some degree he preheated within the chamber surrounding the fire tube.12, thereby substantially increasing the efficiency of the heater .and ensuring a more constant temperature to the discharged air. While the interior of the housing 74 will be heated by heat exchange from the fire tube 12 itself, the rapid and high volume of discharge from the tube 12 will at the same time keep the heat loss within the tube 12 at a minimum, with this heat loss being more than compensated for by the initial heating of the air prior to its introduction into the intake opening 36. Further, it will be appreciated that this heated air within the chamber formed by the housing 72, in conjunction with the insulated walls, top and bottom, provide an effective in sulated enclosure for the fire tube 12.

In operation, upon actuation of the blower 16, air is drawn through the elongated U-shaped duct or fire tube 12 and subsequently discharged toward the area to be heated. Air is initially drawn in through the restricted openings 50 and 60 rearward of the burner head 52, this air constituting the primary combustion-supporting air, the restricted nature of these openings enabling the efficient operation of the blower at various speeds without adversely affecting the operation of the burner unit 14 or the initial combustion. Subsequently, the secondary combustion-supporting air introduced through the opening 36 forward of the burner unit 14 ensures a complete combustion of the gases within the duct, the air introduced through the opening 36 being substantially more than that introduced through the restricted openings 50 and 60. As will be appreciated, the introduction of the secondary combustion-supporting air downstream of the burner unit, by ensuring a complete combustion, eliminates excessive exhaust fumes being expelled from the blower toward the area to be heated, the complete combustion of the fuel being further aided by the constant crosssectional area of the fire tube at least through that portion from the inlet end forward into the bight portion 34. The length and the shape of the fire tube itself is of significance in that it ensures that there is no possibility of the ftame of the burner being drawn into the blower. Further, another significant advantage residing in the particular location of the screen housing openings and 92 is that in the event of any fuel, for example gas, leakage when the device is not being operated, it will be allowed to escape from the housing away from the specific area being heated by the heater unit.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modficatons and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A heater assembly comprising an elongated heatconveying duct means, said duct means including a first inlet end, a second outlet end, a primary air intake formed in said duct means at the first inlet end, a secondary air intake to said duct formed between the inlet end and the outlet end in substantial spaced relation to both, blower means mounted adjacent the duct means outlet endand communicated therewith for drawing heated air from the duct means, said duct means including a substantial angul-ar bend therein between the secondary air intake and the outlet end, said duct means having substantially the same cross-sectional area on both sides of said bend and along the full length thereof, and fuel injection means disposed in said duct means between the inlet end and the secondary air intake.

2. An area heater including an elongated heat-conveying duct means, said duct means comprising first and second aligned sections, said first section including an inlet end portion constituting the duct means inlet, and an outlet end portion, said second section including 'an inlet end portion longitudinally aligned with and spaced from the outlet end portion of the first section, and on outlet end portion constituting the duct means outlet, fuel injection means disposed in the first section inlet end portion, said first section being of a length so as to confine said fuel injection means with the outlet end portion of the first section being located downstream of the fuel injection means, a restricted combustion-supporting air inlet means formed in the first section upstream of the fuel injection mean-s, the space between the outlet end portion of the first section and the inlet end portion of the second section constituting a supplemental combustion air inlet, the first section outlet end portion and the second section inlet end portion being of substantially equal and constant cross-sectional area and defining a straight passage therebetween across the intervening space, blower means mounted adjacent the duct means outlet, said blower means including an air inlet and an air outlet, the blower air inlet being communicated with the duct means outlet for drawing the heated air from the duct means therethrough, and an enlarged insulated housing enclosing and forming a chamber about substantially the entire duct means between the inlet and outlet thereof, said insulated housing including at least one protected air intake means therein in general alignment with the supplemental combustion air inlet for enabling an introduction of air into the chamber for subsequent introduction into the duct means through the supplemental combustion air inlet, said housing being rectangular in shape and including top, side and bottom walls, one protected airintake means being in the top wall generally over the supplemental combustion air inlet, and another protected air inlet means being in that portion of the side wall adjacent the supplemental combustion air inlet.

3. An area heater includiing an elongated heat-conveying duct means, said duct means comprising first and second alinged sections, said first section including an inlet end portion constituting the duct means inlet, and an outlet end portion, said second section including an inlet end portion longitudinally aligned with and spaced from the outlet end portion of the first section, and an outlet end portion constituting the duct means outlet, fuel injection means disposed in the first section inlet end portion, said first section being of a length so as to confine said fuel injection means with the outlet end portion of the first section being locate-d downstream of the fuel injection means, a restricted combustion-supporting air inlet means formed in the first section upstream of the fuel injection means, the space between the outlet end portion of the first section and the inlet end portion of the second section constituting a supplemental combustion air inlet, the first section outlet end portion and the second section inlet end portion being of substantially equal and constant cross-sectional area and defining a straight passage therebetween across the intervening space, blower means mounted adjacent the duct means outlet, said blower means including an air inlet and an air outlet, the blower air inlet being communicated with the duct means outlet for drawing the heated air from the duct means therethrough, an enlarged insulated housing enclosing and forming a chamber about substantially the entire duct means between the inlet and outlet thereof, said insulated housing including at least one protected air intake means therein for enabling an introduction of air into the chamber for subsequent introduction into the duct means through the supplemental combustion air inlet, said housing air intake means being generally aligned with the supplemental combustion air inlet, a support bed carrying said duct means, said blower means and said housing, said second section being reversely bent along the length thereof with the inlet and outlet end portions of this second section opening in the same direction, and with the length of the duct means on both sides of the bend in the second section being substantially equal, and a support frame for blower extension sections orientated above said bed and the duct means mounted thereon, said support frame being mounted directly on said bed and including retaining side rails, said housing being rectangular in shape and including top, side and bottom walls, one protected air intake means being in the top wall generally over the supplemental combustion air inlet, and another protected air intake means being in that portion of the side wall adjacent the supplemental combustion air inlet.

4. An area heater including an elongated heat-conveying duct means, said duct means comprising first and second aligned sections, said first section including an inlet end portion constituting the duct means inlet, and an outlet end portion, said second section including an inlet end portion longitudinally aligned with and spaced from the outlet end portion of the first section, and an outlet end portion constituting the duct means outlet, fuel injection means disposed in the first section inlet end portion, said first section being of a length so as to confine said fuel injection means with the outlet end portion of the first section being located downstream of the fuel injection means, a restricted combustion-supporting air inlet means formed in the first section upstream of the fuel injection means, the space between the outlet end portion of the first section and the inlet end portion of the second section constituting a supplemental combustion air inlet, the first section outlet end portion and the second section inlet end portion being of substantially equal and constant cross-sectional area and defining a straight passage therebetween across the intervening space, blower means mounted adjacent the duct means outlet, said blower means including an air inlet and an air outlet, the blower air inlet being communicated with the duct means outlet for drawing the heated air from the duct means therethrough, and an enlarged insulated housing enclosing and forming a chamber about substantially the entire duct means between the inlet and outlet thereof, said insulated housing including a pair of protected air intake mean-s the-rein in general alignment with the supplemental combustion air inlet for enabling an introduction of air into the chamber for subsequent intro duction into the duct means through the supplemental combustion air inlet, said housing including a top and enclosing side wall, one protected air intake means being in the top generally over the supplemental combustion air inlet, and the other protected air inlet means being in that portion of the side wall adjacent the supplemental combustion air inlet.

5. An area heater including .an elongated heat conveying duct means, said duct means comprising first and second aligned sections, said first section including an inlet end portion constituting the duct means inlet, and an outlet end portion, said second section including an inlet end portion longitudinally aligned with and spaced from the outlet end portion of the first section, and an outlet end portion constituting the duct means outlet, fuel injection means disposed in the first section inlet end portion, said first section being of a length so as to confine said fuel injection means with the outlet end portion of the first section being located downstream of the fuel injection means, a restricted combustion-supporting air inlet means formed in the first section upstream of the fuel injection means, that portion of the duct means be tween the outlet end portion of the first section and the inlet end portion of the second section constituting a supplemental combustion air inlet, the first section outlet end portion and the second section inlet end portion being of substantially equal cross-sectional area and defining, in conjunction with the intervening duct means portion, a straight passage therebetween, blower means mounted adjacent the duct means outlet, said blower means including an air inlet and an air outlet, the blower air inlet being communicated with the duct means outlet for drawing heated air from the duct means therethrough, and an enlarged insulated housing having a top and an encircling side enclosing and forming a chamber about substantially the entire duct means between the inlet and outlet thereof, said insulated housing including one protected air intake means in the top thereof generally over the supplemental combustion air inlet, and another protected air inlet means in that portion of the side adjacent the supplemental combustion air inlet for enabling an introduction of air into the chamber for subsequent introduction into the duct means through the supplemental combustion air inlet.

6. The heater of claim 5 including a support frame for blower extension sections orientated above the enlarged insulated housing, said support frame including a plurality of beams extending lengthwise along said heater, and retaining rails fixed to the opposite ends of said beams and projecting thereabove.

7. The heater of claim 5 wherein said housing is rectangular in shape and includes end walls and a bottom.

8. The heater of claim 7 wherein said second section is reversely bent along a length thereof with the inlet and outlet end portions of this second section opening in the same direction, and with the length of the duct means on both sides of the bed in the second section being substantially equal.

References Cited by the Examiner UNITED STATES PATENTS 1,547,156 7/ 1925 Loepsinger 126-91 2,579,158 12/1951 Scheu 263-19 2,663,362 12/1953 Ransone 263l9 2,703,706 3/1955 Bishop 263l9 FREDERICK L. MATTESON, IR., Primary Examiner. JOHN J. CAMBY, Examiner. 

1. A HEATER ASSEMBLY COMPRISING AN ELONGATED HEATCONVEYING DUCT MEANS, AND DUCT MEANS INCLUDING A FIRST INLET END, A SECOND OUTLET END, A PRIMARY AIR INTAKE FORMED IN SAID DUCT MEANS AT THE FIRST INLET END, A SECONDARY AIR INTAKE TO SAID DUCT FORMED BETWEEN THE INLET END AND THE OUTLET END IN SUBSTANTIAL SPACED RELATION TO BOTH, BLOWER MEANS MOUNTED ADJACENT THE DUCT MEANS OUTLET END AND COMMUNICATED THEREWITH FOR DRAWING HEATED AIR FROM THE DUCT MEANS, SAID DUCT MEANS INCLUDING A SUBSTANTIAL ANGULAR BEND THEREIN BETWEEN THE SECONDARY AIR INTAKE AND THE OUTLET END, SAID DUCT MEANS HAVING SUBSTANTIALLY THE SAME CROSS-SECTIONAL AREA ON BOTH SIDES OF SAID BEND AND ALONG THE FULL LENGTH THEREOF, AND FUEL INJECTION MEANS DISPOSED IN SAID DUCT MEANS BETWEEN THE INLET END AND THE SECONDARY AIR INTAKE. 